International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 6

Number 2

June 2012

209

1 INTRODUCTION

The popular assumption is that a safety of the vessel

is fulfilled by having in vessel's disposal a naviga-

tional chart in proper scale and a device or a method

fixing position on this chart. By this way is possible

to establish the main criterion of the navigational

safety in regions well recognized - distance to the

dangerous objects. In this case the object is univo-

cally defined and charted.

The goal of the author is to establish methods for

assessment of the vessel’s safety during planning

and monitoring of voyage in unsurveyed or poorly

surveyed regions in clear and simple manner that

fulfill requirements of governing regulations (IMO

1993). It includes the navigational information in

world resources of charts and the autonomous

equipment possible to be on board the vessel. One

identifies relations corresponding to the navigational

safety based on field data.

2 MEANS TO SUPPORT THE NAVIGATION

The navigational support of the voyage was divided

into internal and external navigational information.

Internal one was related to the ship's own technical

devices. External one was related to the charts, pilot

books or other information.

2.1 External methods to support the navigation

The main sources of the information for the safe

navigation were sea charts contents. Rest of the in-

formation came from the various nautical publica-

tions. Usefulness of the charts was assessed at first

approach by theirs scale and reliability of the content

(Pastusiak 2010).

2.1.1 Scale of charts

The application of the charts for navigational

purposes was closely correlated with theirs scale.

The electronic chart catalogues (Jeppesen Norway

A/S 2010; Primar Stavanger 2010; Transas Marine

Ltd 2010; UKHO 2010) and the internet chart cata-

logues (IC-ENC, http://www.ic-enc.org, 23-Mar-

2011; NOAA, http://charts.noaa.gov, 16-Jan-10;

NOAA, http://www.nauticalcharts.noaa.gov, 16-Jan-

Ship’s Navigational Safety in the Arctic

Unsurveyed Regions

T. Pastusiak

Gdynia Maritime University, Gdynia, Poland

ABSTRACT: High traffic of the vessels in many regions of the world pressed maritime nations to issue good

quality nautical charts. Vessels could proceed safely on planned voyage using nautical chart and GPS position

receiver. Above popular assumptions were right in well recognized and charted regions. But some regions

were not sufficiently surveyed or not surveyed at all. In this case position fixing system was useless. The only

way was to follow the vessel’s hydroacoustic equipment to find out safe route in between dangers.

The goal of the author was to settle matters of the unsurveyed regions. First question was quality of the in-

formation on charts and role of the vessel’s autonomous hydroacoustic equipment in safety of the navigation.

Second question were safety parameters kept by the research vessel.

210

10; IC-ENC, http://ic-enc.org; Garmin Ltd,

http://www8.garmin.com, 08-Jan-10; Jeppesen

Norway A/S, http://www.c-map.no, 25-Jan-10;

ChartWorld GmbH, http://www.chartworld.com, 29-

Jan-10) introduced division mostly in 6 groups of

charts. It was related to kind of voyage, details of the

information included and the scale of chart (Weintrit

2009). The scale of chart was correlated with posi-

tion error of features placed on chart. It was 0.3 mil-

limetres in lineal measure. In Table 1 there are pre-

sented the position errors of the placed information

(features) related to the worst scales of charts in the

group.

Table 1. Groups of charts and position error of charted features.

___________________________________________________

Group (band) Scale Position error of

charted feature (m)

___________________________________________________

Overview 1:700,000 or smaller 700 or more

General 1;180,000 to 1:350,000 105

Coastal 1:75,000 to 1:180,000 54

Approach 1:12,500 to 1:45,000 13.5

Harbour 1:8,000 to 1:22,000 6.6

Berthing 1:4,000 or greater 1.2

___________________________________________________

2.1.2 Reliability of chart content

Reliability of charts content was described by

date of a survey when source data came from. Actu-

ally used descriptions like “unsurveyed” region,

“poorly examined”, “inaccurately examined”, ”fully

examined” should be correlated with presently being

introduced meaning like Zones of Confidence ZOC

(Gale 2009; UKHO 2004). Zones of Confidence re-

ferred to detection and quality of the measurement

of the features on a seabed. Important matter was

probability of missing (not placing) a navigational

danger on a chart . Zones of Confidence were not

implemented on all charts till now. On many elec-

tronic charts of not well surveyed regions placed

ZOC category “U” that means “unclassified”. The

vessels should use best scale charts for the intended

voyage. The world charts resources were searched in

relation to Murchisonfjorden region at Nor-

daustlandet.

Figure 1. (a) Surveyed region in Isvika (contour line indicates

edge of surveyed lane). (b) Isvika survey region on Svalbard

Table 2. Coverage of Isvika region by charts.

___________________________________________________

Source Scale / Bands SOLAS Kind of chart

___________________________________________________

UKHO general Official paper, ARCS

1:600,000

Norwegian HO 1:100,000 Official Paper

Russia GUNiO 1:200,000 Official Paper

AVCS Transit Official Electronic

ECDIS Service Full Official Electronic

=1:600.000

Primar no coverage ------------ -----------------

Transas Marine 1:200,000 Unofficial Electronic TX-97

Garmin 1:100,000 Unofficial Electronic products

Bluecharts G

armin

Jeppesen 1:100,000 Unofficial Electronic products

Marine C-MAP NT, MAX,

MAX PRO

Jeppesen 1:1,500,000 Official Electronic CM-93/3

Marine C-MAP

SevenCs GmbH Harbour Unofficial Electronic

Navionics ENC

___________________________________________________

2.1.3 Sources of origin of the chart

For purpose of this work reviewed, taken into

consideration and subsequently divided charts as fol-

lows: official, unofficial, „other – bathymetric“ and

„other - non bathymetric. Official charts fulfilled re-

quirements of SOLAS, Chapter V, Regulation 2.2

(IMO 2004) that states “Nautical chart or Nautical

publication is a special purpose map or book, or a

specially compiled database from which such a map

or book is derived that is issued officially by or on

the authority of a Government, authorised Hydro-

graphic Office or other relevant government institu-

tion and is designed to meet the requirements of ma-

rine navigation”. Official charts published by

Hydrographic Offices guaranted systematic updates

of the informational content according to IMO re-

quirements. Zones of Confidence scale should be

available on the chart.

Unofficial charts were of commercial destination.

Theirs informational content had same source of ori-

gin like charts issued by Hydrographic Offices. Un-

official charts not fulfilled SOLAS requirements and

not guaranted systematic updates of the information-

al content. These charts frequently contain additional

commercial information. Vessels operating on unof-

ficial charts are to have and use also up-to-dated of-

ficial charts - at least paper ones.

„Other – bathymetric“ unofficial charts were of

scientific value. The goal of the authors was the

most reliable presentation of depths and sea bottom

relief. Source materials were made frequently with-

out taking into consideration standards of related to

hydrographic surveys described in IHO publication

(IHO 2008) by the persons not being qualified in the

hydrography discipline nor production of official sea

charts. Such charts not included in most cases cor-

rections for sea level in relation to Chart Datum nor

corrections for vertical location of sounder or echo-

211

sounder transducer. Accuracy of sounding was not

estimated nor included in depth reduction. However

„other – bathymetric“ charts were related to hydro-

graphic niches and sometimes were valuable source

of information about sea bottom relief in the region

of interest. Due to lack of better sources of hydro-

graphic information these charts could be usefull for

the initial voyage planning of hydro-graphic surveys.

Informational content allowed to grant them class

from „Coastal” till „Approach”. Appointment of

ZOC class for each „other - bathymetric“ unofficial

chart required individual assessment.

„Other – non bathymetric“ charts were of scien-

tific value. Theirs authors not planned reliable

presentation of depths nor sea bottom relief. Sources

of information related to the sea bottom were in

most cases unknown. However these charts con-

tained informations that allowed to give them ZOC

class „Overview”. For the voyage planning purposes

ZOC scale on „other – non bathymetric“ charts was

not so important.

Reliability of the information content was at-

tributed to the new scale ZOC that replaced infor-

mations about date of last hydrographic survey in

the mentio-ned region. Assumed, that implementa-

tion of new scale of reliability of informational con-

tent on the charts requires prolonged period of time.

It was due to necessity to re-assess date of hydro-

graphic survey and corellated informations on actual

charts that not corresponded with new precise scale

of ZOC.

During process of voyage planning in the unsur-

veyed or poorly surveyed regions should be taken

into consideration the coverage of the region of in-

terest by charts for navigational purposes take into

account all three informative elements: the scale of a

chart, the scale of reliability ZOC and the reliability

of the sources of origin of the chart information.

Table 3. Assessment of external support.

___________________________________________________

Kind Scale One Two Three Four Five Lack

of same level levels levels levels levels of

charts with lower lower lower lower lower chart

norm then then then then then

norm norm norm norm norm

___________________________________________________

Official 6 5 4 3 2 1 0

charts

Unofficial 6 5 4 3 2 1 0

charts

"Other 6 5 4 3 2 1 0

charts –

bathymetric"

"Other 6 5 4 3 2 1 0

charts –

non-bathymetric"

Sum of Maximum possible 24 scores

scores

___________________________________________________

External methods to support the navigation can be

estimated by reviewing available world charts re-

sources and the charts possessed by the vessel. In-

troduced quality scale of support (Table 3) to evalu-

ate external support to the navigation on board the

vessel. The norm was the scale of chart comparable

to the planned kind of the navigation (UKHO 2009;

UKHO 2010; Jeppesen Norway A/S 2010; IC-ENC

2010; ChartWorld GmbH 2010; Primar Stavanger

2009; Weintrit 2009).

For easy assessment of the external support to the

navigation available on board a vessel introduced

relative coefficient of the external support Ce ex-

pressed by Equation 1:

( )

100⋅+++

NBUO

(1)

where C

- the coefficient of the external protection

(%); O - quality rating support by the official charts

in scores from 0 to 6; U - quality rating support by

the unofficial charts in scores from 0 to 6; B - quali-

ty rating support by the “other charts - bathymetric,

in scores from 0 to 6; N - quality rating support by

the “other non-bathymetric charts" in scores from 0

to 6.

The comparison in between potential and actual

support on board the vessel can indicate possibility

and/or necessity of improvement of the external

support quality.

The survey region of Isvika was situated in the

South Eastern part of Murchisonfjorden located on

Nordaustlandet (79°58′N, 18°33′E). The bottom of

Isvika region was rocky, partly coated by a layer of

sediments of glacial origin. From the external

sources of the information (UKHO 2007; The Nor-

wegian Hydrographic Service and Norwegian Polar

Research Institute 1990) found that the surrounding

region not passed any systematical survey. The ships

should navigate with considerable caution because

the sea bottom is very irregular. To be taken into

consideration the existence of not detected danger-

ous banks. Ascertained existence of almost vertical

changes of depth. Even at depths 50 -100 meters can

appear small depths in vicinity. It requires special

caution. The distances to the visible apparent danger

(coast line) on the radar screen during surveys were

about 0.05 nautical miles (Fig. 2a). However, the

coast line was not the closest dangerous feature. The

closest dangers were unknown small depths in close

vicinity of the vessel (Fig. 2b). Reviewing the above

mentioned external information ascertained the

proper scale of a chart required for survey works in

Isvika region as 1:10,000. It corresponded to the

group "Harbour".

The official paper chart (Statens Kartverk 2001)

shown reliable isobaths, features and coast line. The

scale of the chart and the informational content not

212

assured 100% of navigational safety. The official

electronic chart of Transas Marine in scale

1:12,500,000 was not qualified to support naviga-

tion. The unofficial electronic chart Garmin Blue-

chart shown isobaths, features and coast line proper-

ly, but the scale of the chart and the informational

content not assured 100% of navigational safety.

Insufficient external information on the charts re-

quired to support the navigation in poorly surveyed

region (an partly not surveyed at all) of Murchi-

sonfjorden including Kinnvika and Isvika (The

Norwegian Hydrographic Service and Norwegian

Polar Research Institute 1990) with the autonomous

ship’s internal methods detecting dangers to the nav-

igation.

Figure 2. (a) Distance to danger on radar image. (b) Transverse

depths profile at radar position

2.2 Internal methods to support navigation

Internal methods to support the navigation of the

vessel were based on possessed by the vessel tech-

nical resources. They allowed autonomous detection

of underwater dangers. Advantages and disad-

vantages of each method not clarified superiority

any of below mentioned methods.

2.2.1 Sonar looking forward

The sonar looking forward allowed detection of

underwater objects (features) in front of the vessel.

The image of the situation was presented on heading

in vertical and horizontal sections. In case sonar

looking forward was only one electro acoustic de-

vice being on board vessel, one could continue a

safe voyage in any direction.

2.2.2 Multibeam echosounder

The multibeam echosounder detected underwater

objects (features) in transverse plane of the vessel. It

not informed about the situation in front of the ves-

sel. In case the multibeam echosounder was only one

electro acoustic device being on board the vessel in

unsurveyed regions, one could continue safe voyage

across planned direction of the voyage. It required

proceed along the lanes of previous measurements of

the multibeam echosounder.

2.2.3 Single-beam echosounder

The single-beam echosounder detected underwa-

ter objects along perpendicular line under the vessel.

It not informed about the situation in front of the

vessel. In case the single-beam echosounder was on-

ly one electro acoustic device being on board the

vessel in unsurveyed regions, one could extrapolate

a distance to the potential underwater danger from

tendency of depth changes. The single-beam echo-

sounder was not a fully autonomous device nor as-

sured 100% safety of the navigation.

2.2.4 Echosounder on boat proceeding in front of

the vessel

The boat proceeding in front of the vessel was

equipped with single-beam echosounder. Results of

this method were very similar to sonar looking for-

ward. Safety output depended on qualifications of

the boat crew and cooperation in between the boat

and the vessel. It required good radio information

exchange.

Quality of internal methods to support the naviga-

tion ascertained by reviewing equipment possessed

by the vessel. Proposed scale was presented in Ta-

ble 4.

Table 4 . Assessment of internal support.

___________________________________________________

Device being Efficient and Efficient and Inefficient or

aboard reliable not reliable lack device

Sonar looking 2 1 0

forward

Multibeam 2 1 0

echosounder

Single-beam 2 1 0

echosounder

Echosounder on 2 1 0

boat proceeding

forward

___________________________________________________

Sum of scores Maximum possible 8 scores

___________________________________________________

For easy assessment of internal support to the

navigation available on board the vessel was intro-

duced relative coefficient of internal support C

ex-

pressed by Equation 2:

( )

100⋅+++

RSMF

(2)

213

where C

– the coefficient of the internal support (%)

; F - quality rating support by the sonar looking for-

ward in scores from 0 to 2; M - estimation of support

by the multibeam echosounder in scores from 0 to 2;

S - estimation of support by the single-beam echo-

sounder in scores from 0 to 2; R – estimation of sup-

port by the boat with the echosounder in scores from

0 to 2.

3 ESTIMATION OF THE DISTANCE TO THE

DANGERS WITH THE MULTIBEAM

ECHOSOUNDER

The assessment of navigational safety in the regions

well recognized and charted was made in relation to

the superficial and underwater dangers plotted on the

sea charts. The information about the dangers on

Svalbard not existed or was not sufficient or was not

reliable. The assumed “danger” was unknown region

(„blank place”) out of the edge of not processed in-

formation from the multibeam echosounder (Fig.3a).

The criterion of danger was the distance to this edge

(Fig.3b). The navigator made continuous interpreta-

tion of multibeam echosounder image. Curvature of

sea bottom was presented by serial of dots. The con-

tiguous line to the most external dots allowed ex-

trapolation of the sea bottom curvature up to sea sur-

face. It gave additional reserve to the expected

danger. In some cases was not easy to identify falla-

cious dots from whole sea bottom line. In depend-

ence from the navigator decision various contiguous

lines could be taken into consideration. This led to

receive various reserve of expected distance to the

“danger”.

The sea charts of Murchisonfjorden region not as-

sured safe navigation. These charts based on the in-

formation from the paper chart in scale 1:100.000

(Statens Kartverk 2001). Theirs information content

not shown all features discovered by the multibeam

echosounder. In some cases the sea charts shown in-

adequate locations of the coast line and the bottom

features. The British and Norwegian pilot publica-

tions contained very limited information. Same time

these publications advised mariners about almost

vertical high changes of depths in the western part of

Murchisonfjorden (The Norwegian Hydrographic

Service and Norwegian Polar Research Institute

1990). Taking into considerations the International

Hydrographic Organization (IHO) regulations,

soundings and changes of depths described above,

the regions of Isvika and Murchisonfjorden should

be treated as insufficiently surveyed and partly as

unsurveyed regions (IHO 1994; IHO 2009; The

Norwegian Hydrographic Service and Norwegian

Polar Research Institute 1990).

Figure 3. (a) Multibeam echosounder image, (b) The “un-

known” area on multibeam echosounder image and probable

distance to danger“

3.1 Method of analysis of field data

Survey data collected by multibeam echosounder

Sea Beam 1180 of ELAC Nautik GmbH on r/v “Ho-

ryzont II” under IPY- Kinnvika expedition 2009.

During work with the multibeam echosounder made

continuous pinging and record of depths. The vessel

followed route according to the voyage plan. In

some cases the vessel deviated from planned route to

avoid uncharted dangers or to collect more data of

unknown area. The movement along the edge of the

previously surveyed lane was also included into con-

sideration.

Figure 4. Depths along the edge of survey lane

The main aim of analysis was to find out correla-

tions in between distance to the danger (the criterion

of International Maritime Organization), depths and

longitudinal and transverse changes of depths at the

edge of surveyed lane. The analysed distances and

bottom profiles (Fig.4) were not related to the coast-

line. Also they were not related to any isobaths.

They were related to the non-linear movement and

position of the vessel. This movement was the result

of subjective assessment of the safety by the naviga-

tor. Position of the transducer of the multibeam

echosounder was point of reference for depths and

214

distances. The correlation represented by equations

in between navigational safety parameters were re-

ceived by PAST (Paleontological Statistics) software

of Natural History Museum in Oslo.

3.2 Results

Analyzing series of data received during survey

identified formula (Eqn 3) showing correlations in

between distance to danger and longitudinal changes

of depths.

hD ∆−= 2741.01484.19

(3)

where D – distance to the edge of the surveyed lane

interpreted as distance to the danger (m);

∆

–

change of depths along the edge of the surveyed lane

on the longitudinal section of 100 meters (m).

Same way identified formula (Eqn 4) showing

correlations in between distance to the danger and

transverse changes of depths.

hd ∆−= 8512.05455.19

(4)

where d − distance to the edge of the surveyed lane

interpreted as distance to the danger (m);

∆

–

change of depths along the edge of the surveyed lane

on transverse section of 100 meters (m).

4 CONCLUSIONS

The electronic charts made by various makers may

be made in the different standard then accepted by

the ship's ECDIS system being on board the vessel.

In such case the ship-owner must solve dilemma of

undertaking high buying costs of second ECDIS sys-

tem that will serve for other electronic charts ful-

filling necessities of the planned voyage. Purchase

of next ECDIS system for a single or occasional

voyage seems loose the financial competition with

the paper or raster charts as far as such alternative

exists.

The makers of the electronic charts being under

pressure of strict requirements of ZOC are forced to

downgrade quality of presented information on pa-

per charts even for few groups. Issuing gratuitous

unofficial charts (NOAA, http://charts.noaa.gov;

http://www.nauticalcharts.noaa.gov, 16-Jan-10) or

with considerably lower price than theirs official

equivalents (Garmin Ltd, http://www8.garmin.com,

08-Jan-10; Jeppesen Norway A/S, http://www.c-

map.no ,25-Jan-10) is favourable signal for sea

charts users. Planning of navigational voyage sup-

port of the vessel seems to be simple and clear in

case exist the official nautical charts of suitable pa-

rameters for the intended kind of the voyage.

The goal of author is to elaborate simple appraisal

method for planning navigational voyage support in-

cluding unsurveyed or inaccurately surveyed re-

gions. The external and internal methods to support

the navigation were described. Proper assessment

scales and coefficients were proposed. Above meth-

od gave tool for appraisal of the navigational voyage

plan in clear and simple manner so convenient for

organizers and performers of a voyage. By this way

is possible to detect the weaknesses of vessel’s pre-

paredness and improve it.

The unknown regions ("blank places") on screen

of the multibeam echosounder are treated with dis-

trust by the navigators. The distance to the edge of

unsurveyed region that navigator try to hold is ap-

proximately 20 meters. This distance is inversely

proportional to the tendency of changes. The angular

dimensions of the image on screen (visual estimation

of not processed image of the sea bottom relief), the

range of beams of the echosounder and the distance

to the edge of the surveyed lane are essential for es-

timation of safety. Identification of more detailed

correlations requires however further research.

REFERENCES

Gale, H., 2009: From paper charts to ECDIS, A practical voy-

age plan: Part 3, Seaways November 2009, p. 5 - 9.

IHO, 1994: Hydrographic Dictionary, Part I, Volume I, Eng-

lish, Special Publication No. 32, Fifth Edition, Monaco

1994, 280 pp.

IHO, 2008: IHO Standards for Hydrographic Surveys, Special

Publication No 44, Fifth Edition, Monaco February 2008,

pp.28

IHO, 2009: Regulations of the IHO for international (INT)

charts and charts specifications of the IHO, Edition 3.006,

April 2009, 392 pp.

IMO, 1993: Resolution A.741(18), International Safety Man-

agement Code, 4 November 1993.

IMO, 2004: SOLAS consolidated edition 2004, London,

pp.628.Jeppesen Norway A/S, 2010: C-MAP Chart Catalog

v.2.4.0.8.

Pastusiak, T., 2010: Problems of coverage of unsurveyed re-

gions by electronic charts [in Polish], Logistyka 2/1010,

ISSN 1231–5478, p 2069-2086.

Primar Stavanger, 2009: Primar Chart Catalogue 4.3.

Statens Kartverk 2001: NO537, Paper chart, Svalbard, Hinlo-

penstretet N, scale 1:100,000.

The Norwegian Hydrographic Service and Norwegian Polar

Research Institute, 1990: Den Norske Los, Arctic Pilot,

Vol. 7, 2nd Edition, 433 pp.

Transas Marine Ltd, 2010: Transas Chart World Folio

v.3.2.332, WF 28.

UKHO, 2004: NP100, The Mariners Handbook, 8th Edition,

260 pp.

UKHO, 2007: NP11 Arctic Pilot, Edition 2004, Correction

2007.

UKHO, 2010: Admiralty Digital Catalogue v.1.6.0.

UKHO, 2009: Catalogue of Admiralty Charts and Publications

NP131, 2009 Edition.

Weintrit, A., 2009: The electronic chart display and infor-

mation system (ECDIS) - An operational handbook, Boca-

Raton - London - New York – Leiden, CRS Press, Taylor &

Francis Group, ISBN-13: 978-0-41548246-2, 1101pp.